Would/Do they have the recipe?

Question

What's the difference between two phrase:

1. Would they have the recipe?
2. Do they have the recipe?

Answer 1

Would they have the recipe?

The use of would asks if it is likely "they" have the recipe. The answer may be "yes" but it is still not certain that "they" have the recipe to which you refer.

Do they have the recipe?

...whereas this second sentence asks specifically asks if "they" have the recipe and an affirmative answer would required knowledge that "they" do actually have the recipe.

Answer 2

Both of your examples are correct, understandable, and have the same meaning. A slight nuance might be

Do they have the recipe?

has the feeling that you expect "they" have the recipe, whereas

Would they have the recipe?

might be more tentative in thinking "they" have the recipe.

Answer 3

Would they have the recipe?

This question asks if they probably have the recipe.

Do they have the recipe?

This question asks if they certainly have the recipe.